Straightforward Parking Lot Design

Parking lot design is a snapshot of a civil engineer’s skill set, and
the elements needed to be good at it are also the elements needed for
good overall site engineering. It might seem rudimentary to some. But
like anything else that is done well, it should be done with purpose.

The parking lot is both a necessary part of our transportation system
and a large cost of real estate development. A parking area’s primary
responsibility is to change drivers and passengers into pedestrians and
back again.

To keep costs down, parking lot design has to be
practical from the start. Designed properly, parking lots and
facilities can also be aesthetically pleasing and environmentally sound.

Functional and Operational

At first glance, a parking lot is simply an expanse of pavement.
Good parking lot design, however, incorporates practical human needs
with aesthetic considerations and environmental prudence.

Note: We don't try to elevate parking lot design to a higher consciousness
or something, it’s just that parking lots are expensive and permanent
site fixtures and should be planned and designed with the same care as
the buildings they serve.

Drive lanes and parking stalls have
to be sized and oriented correctly to allow easy driver navigation and
vehicle passage. Pedestrians need safe and convenient passage to and
from their vehicles. There’s no use making a parking lot
environmentally sound and beautifully landscaped if it doesn’t work.
That being said, good parking lot design incorporates aesthetics and
environmental remedies with function in a way that keeps construction
and maintenance costs reasonable.

Driver, Passenger, Pedestrian, and Vehicle Safety

Parking lot lighting is required, unless the lot is gated to
eliminate access at night, to provide safe use. It’s obvious that a
properly illuminated parking facility enhances driver and pedestrian
vision, and deters violence and theft. But the choice of lighting is
important as well.

Sodium and mercury vapor lighting (the orange
and blue-white colored lights, respectively, usually used on public
streets) illuminate in narrow bands of the visible light spectrum and
therefore do not reveal colors well. Better choices are metal halide
and LED lighting for color rendition.

Site, Architecture and Land Use Integration

Apart from functionality, integration into the site is an important
aspect of parking lot design. Using existing site features, landscape
design, and integration of building architecture helps to both define
and visually soften parking lots.

A great opportunity for site
integration is the incorporation of existing mature trees into the
parking layout and design. To do this, the orientation of drives and
parking stalls are configured to locate mature trees into parking
islands and outside the pavement.

Environmental Considerations

Storm water runoff

Parking lots produce much of the storm water runoff from a developed
site. Local ordinances generally require that the peak runoff rate from
a developed site not exceed the preexisting rate. Common law also
finds that a property owner may not direct storm water onto an adjacent
property in excess of preexisting drainage patterns. Additionally, some
local governments require the reduction of pollutants in storm water
runoff prior to discharge to surface waters or into a public storm water
collection system.

Reduction of the peak storm water runoff rate
is accomplished by restricting the flow offsite. This requires that
water be detained on the site, usually holding the storm water in the
ubiquitous detention basin. If not designed carefully into the site,
detention basins can be an eyesore. At sites where a natural look is
desired, low areas of the site should be reserved for storm water
detention. If a formal look or water features are desired, storm water
detention can be incorporated into ponds and lakes.

A storm water
detention system that incorporates bioswales, rain gardens, and
vegetated filters reduces pollutants, reduces peak flows, and just looks
better. Using these natural systems uses more land because of the
filtration area provided. At sites where the land available for parking
lots is restricted, natural detention systems can be difficult, but not
impossible, to implement. Based on the extent of green storm water and
landscape buffer requirements, the parking lot design will need about 5
to 15 percent more area to implement all these features.

Heat Island Effect

Pavement absorbs the sun’s energy and releases it as heat. To reduce
the heat island effect, parking lots should be shaded from the sun with
boundary and internal arrangement of trees. Portland cement concrete
pavement, being lighter colored than asphalt, will reflect more light
and absorb less energy.

Snow

Parking lots in northern climates need to facilitate snow plowing and
snow storage. Curb cuts, or better yet, pavement edges without curbs,
should be provided at ends of circulation lanes to allow snow plows to
push snow away from parking areas without having to lift the blade. No
matter how well they mark the curbs, plow drivers will hit and damage the curb!

Alternatives and New Ideas

The search engines return a lot of ideas and images related to
parking. There are found “solar trees” for charging electric
cars. These far-out concepts seemed to have a
similar feature: To promote alternative energy use and reduce the
parking lot carbon footprint.

Efficient and less costly
transportation is good. When the day for solar trees arrives, parking
lot design will still have to incorporate practical solutions to driver
and vehicle navigation, pedestrian safety, handicap accessibility, storm
water runoff, and visual impact.

Engineering. Simply.

Prince Engineering, PLC is a designer and engineer of successful land
developments. I would like to talk to you, on me, about your
development plan. Call me, Rick Prince, at (888) 418-2695 and see if Prince is a good fit
for you. I think you’ll be glad you did.

Send Rick Prince, owner and Engineering Principal, a message (This link takes you to the email contact form) or simply call for discussion and answers. We’re inclusive, not exclusive.
That means engineering is done in a way that’s easy, understandable
and productive. You’ll enjoy what you can build with Prince
Engineering, PLC.